Ultrasound of acute GI tract conditions

Basic practices for gastrointestinal ultrasound

The standard diagnostic modalities for gastrointestinal (GI) diseases have long been endoscopy and barium enema. Recently, trans-sectional imaging modalities, such as computed tomography and magnetic resonance imaging, have become increasingly utilized in daily practice. In transabdominal ultrasonography (US), the bowel sometimes interferes with the observation of abdominal organs. Additionally, the thin intestinal walls and internal gas can make structures difficult to identify. However, under optimal US equipment settings, with identification of the sonoanatomy and knowledge of the US findings of GI diseases, US can be used effectively to diagnose GI disorders. Thus, the efficacy of GIUS has been gradually recognized, and GIUS guidelines have been published by the World Federation for Ultrasound in Medicine and Biology and the European Federation of Societies for Ultrasound in Medicine and Biology. Following a systematic scanning method according to the sonoanatomy and precisely estimating the layered wall structures by employing color Doppler make diagnosing disease and evaluating the degree of inflammation possible. This review describes current GIUS practices from an equipment perspective, a procedure for systematic scanning, typical findings of the normal GI tract, and 10 diagnostic items in an attempt to help medical practitioners effectively perform GIUS and promote the use of GIUS globally.

Point-of-care Ultrasound of the Gastrointestinal Tract

The widespread use of portable ultrasound scanners has promoted the concept of point of care ultrasound (POCUS), namely "ultrasound performed bedside and interpreted directly by the clinician." The purpose of this short review is to outline how POCUS can be used in patients with diseases of the gastrointestinal (GI) tract. POCUS is not a replacement for comprehensive ultrasound, but rather allows physicians immediate access to clinical imaging for rapid diagnosis and efficient work-up and treatment of the patients. There are many indications for doing POCUS of the GI tract, including abdominal pain, diarrhea, palpable masses, and to detect fluid or free air in the abdominal cavity. To improve the visibility of deeper parts of the abdomen, the graded compression technique with the scan head is useful. During POCUS, the operator should look for signs of severe pathology including target lesions, the pseudo-kidney sign, the onion sign, dilated bowel loops, gastric retention, free fluid, and free air, depending on the actual clinical problem. We conclude that POCUS of the GI tract is very useful to provide a rapid diagnosis in many clinical scenarios.

Differentiation of Yersinia enterocolitica enteritis from other bacterial enteritides by ultrasonography: A single-center case-control study

BACKGROUND

The diagnosis of Yersinia enterocolitica (Ye) enteritis is not easy because detection from stool culture is more difficult for Ye than for other bacterial enteritides. The establishment of characteristic ultrasonographic findings for Ye enteritis would help improve the detection rate of Ye enteritis along with performance of several cold cultures. This would facilitate appropriate selection of antibiotics based on antimicrobial susceptibility testing and contribute to a more accurate understanding of local public health. This study aimed to retrospectively compare ultrasonographic findings and clinical features between children with Ye enteritis and other bacterial enteritides.

METHODS

We identified patients treated for Ye enteritis (Ye group; n = 27) or other bacterial enteritides (Other enteritis group; n = 29) between 2014 and 2018. Ultrasonographic findings (including mean maximum diameter and mean major-minor axis ratio of ileocecal lymph nodes, wall thickness of the terminal ileum, and presence of a pericecal hyperechoic region), clinical symptoms, and laboratory findings at first visit were compared between groups.

RESULTS

No difference in mean maximum diameter of ileocecal lymph nodes was seen between groups. However, mean major-minor axis ratio of ileocecal lymph nodes was lower in the Ye group than in the Other enteritis group (p < 0.001). Presence of a pericecal hyperechoic region was more frequent in the Ye group than in the Other enteritis group (p < 0.001). The combined presence of a mean ileocecal lymph node major-minor axis ratio <1.51 and a pericecal hyperechoic region offered 100% sensitivity.

CONCLUSION

Characteristic ultrasonographic findings identified in this study may improve ultrasonographic differentiation of Y. enterocolitica enteritis from other bacterial enteritides.

Gastrointestinal Ultrasound (GIUS) in Intestinal Emergencies - An EFSUMB Position Paper

An interdisciplinary group of European experts summarizes the value of gastrointestinal ultrasound (GIUS) in the management of three time-critical causes of acute abdomen: bowel obstruction, gastrointestinal perforation and acute ischemic bowel disease. Based on an extensive literature review, statements for a targeted diagnostic strategy in these intestinal emergencies are presented. GIUS is best established in case of small bowel obstruction. Metanalyses and prospective studies showed a sensitivity and specificity comparable to that of computed tomography (CT) and superior to plain X-ray. GIUS may save time and radiation exposure and has the advantage of displaying bowel function directly. Gastrointestinal perforation is more challenging for less experienced investigators. Although GIUS in experienced hands has a relatively high sensitivity to establish a correct diagnosis, CT is the most sensitive method in this situation. The spectrum of intestinal ischemia ranges from self-limited ischemic colitis to fatal intestinal infarction. In acute arterial mesenteric ischemia, GIUS may provide information, but prompt CT angiography is the gold standard. On the other end of the spectrum, ischemic colitis shows typical ultrasound features that allow correct diagnosis. GIUS here has a diagnostic performance similar to CT and helps to differentiate mild from severe ischemic colitis.

Advanced Fusion Imaging and Contrast-Enhanced Imaging (CT/MRI-CEUS) in Oncology

Fusion imaging depicts an innovative technique that facilitates combining assets and reducing restrictions of advanced ultrasound and cross-sectional imaging. The purpose of the present retrospective study was to evaluate the role of fusion imaging for assessing hepatic and renal lesions. Between 02/2011-08/2020, 92 patients in total were included in the study, of which 32 patients had hepatic lesions, 60 patients had renal lesions. Fusion imaging was technically successful in all patients. No adverse side effects upon intravenous (i.v.) application of SonoVue® (Bracco, Milan, Italy) were registered. Fusion imaging could clarify all 11 (100%) initially as indeterminate described hepatic lesions by computed tomography/magnetic resonance imaging (CT/MRI). Moreover, 5/14 (36%) initially suspicious hepatic lesions could be validated by fusion imaging, whereas in 8/14 (57%), malignant morphology was disproved. Moreover, fusion imaging allowed for the clarification of 29/30 (97%) renal lesions initially characterized as suspicious by CT/MRI, of which 19/30 (63%) underwent renal surgery, histopathology revealed malignancy in 16/19 (84%), and benignity in 3/19 (16%). Indeterminate findings could be elucidated by fusion imaging in 20/20 (100%) renal lesions. Its accessibility and repeatability, even during pregnancy and in childhood, its cost-effectiveness, and its excellent safety profile, make fusion imaging a promising instrument for the thorough evaluation of hepatic and renal lesions in the future.

Intestinal ultrasonography in adults with Crohn's disease: a 2020 update

In the last years intestinal ultrasonography (IUS) has increased its role in the management of inflammatory bowel diseases (IBD), that include Crohn's disease (CD) and ulcerative colitis. This is due to the fact that IUS is a non-invasive, inexpensive, and well-tolerated examination technique. Furthermore, it allows a real-time diagnosis with no radiation exposure. Usually, convex and linear probes with frequency between 3.5 and 12 MHz are used, also with the Color- Power Doppler. Focusing on CD, the IUS images of clinical interest are: bowel wall thickening (greater than 3 mm), pseudostratification and the wall vascularization. Moreover, IUS demonstrates inflammatory mass, loss of colonic haustration and the complications of the disease, such as stenosis, abscesses, and fistulas as well as other extraintestinal manifestations, such as lymph node enlargement and changes in the appearance of the mesenteric adipose tissue (creeping fat). Oral and intravenous contrast are used to obtain a better visualization of the bowel wall and to increase the diagnostic accuracy of IUS. In particular, intravenous contrast, administered during the procedure, allows to differentiate between active disease (bowel wall enhancement) and the fibrostenotic complications. Contrast-enhanced ultrasonography (CEUS) was proven to be useful in the follow-up and the disease recurrence detection. Beyond the support in the initial diagnosis, IUS has an important role in the follow-up of patients with CD, to monitor the response to the medical therapy and to detect possible complications. Furthermore, it can predict the recurrences after surgery, with more accuracy if Color-Doppler is used.

Pitfalls in ultrasound imaging of the stomach and the intestines

The gastrointestinal tract is an extraordinary human organ in terms of its morphology and function. Its complex structure and enormous length as well as frequent presence of gas discourage many doctors performing ultrasound examination from its exploration. Moreover, there are anatomical structures in multiple locations which can mimic certain abnormalities. It is difficult to present an exhaustive account of the problem of gastrointestinal tract ultrasound imaging errors in a single work; therefore, this study focuses mainly on false positive errors which usually result from a lack of knowledge of anatomical variants of the gastrointestinal tract structure. In the case of the stomach, rugae and muscle layer thickening towards the pylorus have been mentioned, which constitute variants of the structure of this organ examined when empty. Diagnostic pitfalls in the small intestine may include the dudenojejunal flexure (ligament of Treitz), the horizontal part of the duodenum and the ileocaecal valve. The status of the apparent lesions in all of the cases mentioned will be resolved following fluid intake by the patient. In the colon, the varied structure of semilunar folds should be taken note of. Their large thickness can warrant suspicion of wall invasion or a polyp. In addition, the study emphasises the importance of appropriate preparation of a patient for gastrointestinal tract examination since it determines the accuracy of the diagnosis. The authors also take note of common ‘sins’ of physicians such as hasty examination and failure to comply with the stomach and appendix examination protocol.

Small Bowel Ultrasound beyond Inflammatory Bowel Disease: An Updated Review of the Recent Literature

The use of bowel ultrasonography (US) for the evaluation of gut diseases has increased in recent years and has been proven to provide a widely available, non-invasive and inexpensive method for the initial work-up and follow-up of different intestinal diseases, limited mostly by technical challenges posed by the patient's anatomy. The present review aims to provide an extensive overview of the main pathologic features at US examination of intestinal diseases other than inflammatory bowel disease, both acute (e.g., acute appendicitis, colonic diverticulitis, infectious diseases and ischemic conditions) and chronic (e.g., celiac disease, cystic fibrosis and other enterocolites). The identification of typical US features may help in the diagnostic process and guide the treatment approach. Therefore, the application of knowledge of the US appearance of gastrointestinal diseases is of relevance in enabling greater diagnostic performance and better patient management.

Abdominal ultrasonography for patients with abdominal pain as a first-line diagnostic imaging modality

The utility and limitations of abdominal ultrasonography (US) were retrospectively evaluated as a first-line diagnostic imaging modality in patients with abdominal pain. Hospital records from patients subjected to abdominal US as a first-line diagnostic imaging examination at the National Hospital Organization Shimoshizu Hospital (Yotsukaido, Japan) from April 2010 to April 2015 were analyzed. Only those patients who underwent abdominal US to diagnose abdominal symptoms were included in the present study. All patients with prior diagnostic imaging examination findings were excluded from the study in order to reduce bias of results. The analyzed patients included 39 males with an average (mean ± standard deviation) age of 65.8±18.8 years and 37 females with an average age of 53.7±19.3 years. Diagnosis with abdominal US was in agreement with the final diagnosis in 66 of the 76 patients. Final diagnosis of symptoms by abdominal US was not successful in the remaining 10 patients who required further investigation. Acute cholangitis, acute cholecystitis, acute pancreatitis, acute appendicitis, colonic diverticulitis and spleen rupture were correctly diagnosed. Different types of cancer, including colorectal cancer, were also successfully diagnosed. Bile duct cancer and sigmoid colon volvulus could not be diagnosed by abdominal US due to the presence of intestinal gas. Abnormal findings were detected using abdominal US, but the diagnosis required additional consultation with gynecologists. Abdominal US was suitable for patients with abdominal symptoms. It is recommended that patients undergo further diagnostic imaging or consultation with gynecologists when large gas bubbles are present or gynecological conditions are suspected.

Transient ischemic jejunitis due to symptomatic isolated superior mesenteric artery dissection: case report and review of literature

Acute abdominal pain is one of the most common conditions encountered in the emergency department. The differential diagnosis of acute abdominal pain is extensive and identifying the underlying etiology can be challenging. We report a case of acute transient ischemic jejunitis due to symptomatic isolated superior mesenteric artery dissection in a patient with no cardiovascular risk factors or autoimmune diseases. Symptomatic isolated superior mesenteric artery dissection is a rare cause of acute abdominal pain usually treated in the surgical department. The patient had criteria for conservative treatment and rapidly recovered. We highlight a rare condition which should be taken into account for the differential diagnosis of acute abdominal pain.

Detection of gastric cancer using transabdominal ultrasonography is associated with tumor diameter and depth of invasion

Gastric cancer is occasionally diagnosed using transabdominal ultrasonography (US) during screening or investigation of patients with abdominal symptoms. Therefore, the present study analyzed the association of the tumor diameter, pathological T (pT) staging and depth of invasion with the detection of gastric cancer using US. Patient records were analyzed retrospectively and 13 patients were enrolled, who underwent US screening prior to endoscopic mucosal resection, endoscopic submucosal dissection or surgery. In total, 5 patients were diagnosed with gastric cancer using US (positive detection group), while US was unable to detect the gastric cancer in 8 patients (negative detection group). The tumor diameter and depth of invasion were determined by pathologists. One-way analysis of variance or the χ² test was performed. Wall thickness in gastric cancer cases ranged between 7 and 20 mm (mean, 12.2±5.9 mm), as measured using abdominal US. The hemoglobin level was significantly lower in the positive detection patients compared with the negative detection patients (P=0.0455). In addition, the diameters of the gastric wall in the negative and positive detection patients were 24.5±16.4 and 54.4±26.2 mm, respectively (P=0.0266). These results indicate that gastric cancer in the positive detection patients were at a more advanced-stage compared with that in the negative detection patients. Furthermore, gastric cancer with a stage over pT2 was diagnosed using abdominal US (P=0.0242), whereas stage pT1a gastric cancer was not detected by abdominal US. Gastric tumors invading deeper than the submucosa were diagnosed using US (P=0.0242). However, the gastric cancer cases limited to the mucosa remained undetected. In conclusion, the detection of gastric cancer correlated well with the tumor diameter, pT staging and depth of invasion.

Contrast-enhanced ultrasound in the differentiation between phlegmon and abscess in Crohn's disease and other abdominal conditions

AIM

To evaluate the diagnostic accuracy of the contrast-enhanced ultrasound (CEUS) to differentiate between intra-abdominal phlegmon and abscess.

METHODS

We retrospectively reviewed all contrast-enhanced ultrasound performed between June 2006 and May 2012 to identify patients with the terms "inflammatory mass", "phlegmon" or "abscess" on the sonographic report. The initial CEUS report was used for the diagnosis of phlegmon or abscess.

RESULTS

71 inflammatory masses in 50 patients were identified in CEUS examination. 57 masses, 21 phlegmons and 36 abscesses, were confirmed by other imaging techniques, percutaneous drainage or surgery. CEUS specificity for the diagnosis of abscess was 100%. Kappa coefficient between CEUS and other techniques in the diagnosis of phlegmon or abscess was excellent (kappa=0.972). Only in one patient surgery detected a small abscess (<2 cm) within a phlegmon that not was detected by CEUS. Statistically significant differences were found between the size of the abscesses before and after contrast agent injection. The interobserver agreement in the diagnosis of phlegmon or abscess was excellent (kappa=0.953).

CONCLUSIONS

CEUS is an accurate method for differentiating between intra-abdominal phlegmon and abscess in gastrointestinal conditions, especially in CD. Its use may help to better define the size of the collections and avoid other techniques that use ionizing radiation. CEUS should be used to confirm an inflammatory mass identified at US.

Transabdominal ultrasound for bowel evaluation

This article considers the case for a strategic place for ultrasound (US) bowel evaluation focusing on three common clinical contexts. These include imaging for suspected acute appendicitis and acute diverticulitis, as well as the role of US in a multimodality approach for the diagnosis and management of inflammatory bowel disease and associated complications.

The importance of ultrasonographic pneumatosis intestinalis in equine neonatal gastrointestinal disease

REASONS FOR PERFORMING STUDY

Recognising the presence of a necrotising component of the gastrointestinal disease may be clinically useful in ill equine neonates.

OBJECTIVES

To study the importance of abdominal sonograms in neonatal foals suffering from gastrointestinal conditions and to describe the clinical features of necrotising gastrointestinal disease.

HYPOTHESIS

There is a subgroup of neonates with sonographically detectable pneumatosis intestinalis (PI), reflecting a necrotising disease.

METHODS

Records of foals aged < or = 7 days hospitalised from 2005 to 2009 with signs of gastrointestinal disease were evaluated (n = 89). The association of sonographic, clinical and clinicopathological signs with necrotising gastrointestinal disease and outcome was determined.

RESULTS

PI was imaged in 19 foals. Twenty-seven foals were classified as having necrotising gastrointestinal disease based on the presence of gastrointestinal signs (colic, diarrhoea, gastric reflux or abdominal distension) and sonographic PI (n = 19), surgical (n = 2) or pathological (n = 6) evidence of gastrointestinal necrosis. There was a difference between survival rate in foals with and without necrotising disease (33.3 and 69.4%, respectively, P = 0.005) or foals with and without PI detected sonographically (36.8 and 72.1%, respectively, P = 0.023). PI was the only sonographic finding associated with outcome. Prematurity, the presence of blood in the faeces, gastric reflux, abdominal distension, abnormal echogenicity of the colon and the lowest white blood cell count during hospitalisation were associated with necrotising gastrointestinal disease (P < 0.05).

CONCLUSIONS AND POTENTIAL RELEVANCE

Abdominal sonograms have prognostic value in neonatal gastrointestinal disease. PI and the presence of necrotising gastrointestinal disease were common and associated with a poor prognosis.

Infections and infestations of the gastrointestinal tract. Part 1: bacterial, viral and fungal infections

The purpose of this article is to review the imaging findings of various infections affecting the gastrointestinal tract. Barium examinations, computed tomography (CT), magnetic resonance imaging (MRI), and ultrasonography all play an important role in the diagnostic workup of gastrointestinal tract infections. Knowledge of differential diagnosis, sites of involvement, and typical imaging features of different infections can help in accurate diagnosis and guide treatment.

Indices of diagnostic abdominal ultrasonography in acute appendicitis: influence of gender and physical constitution, time evolution of the disease and experience of radiologist

OBJECTIVE

To assess the value of abdominal ultrasonography in the diagnosis of acute appendicitis and the influence of gender, physical constitution, experience of the radiologist and the time evolution of the disease on the results of diagnostic indices.

METHODS

We prospectively evaluated 156 patients with clinical diagnosis of acute appendicitis who underwent laparoscopic appendectomy and abdominal ultrasonography, together with pathology of the excised appendices. Patients were allocated in relation to BMI in both groups (below or above 25 kg/m²) and radiologists, in three groups according to their professional experience (less than five years, between five and 10 years and more than 10 years). The survey also assessed the influence of gender and time of disease progression using the median of 36 hours.

RESULTS

The sensitivity and specificity of abdominal ultrasonography for diagnosing appendicitis were 64.9 and 72% respectively. Gender, body mass index, length of experience of the radiologists in the three groups and time of onset of symptoms showed no significant differences in the establishment of sonographic diagnosis of acute appendicitis.

CONCLUSION

The abdominal ultrasonography showed low sensitivity and specificity and little contribution to the diagnosis of acute appendicitis. Gender, physical constitution, the experience of the radiologist and time of onset of symptoms did not affect the outcome of the sonography.

Recent advances in intestinal imaging

In recent years, advances in scanner technology and competition from other specialties have produced rapid changes in the way the intestines are imaged. MRI and CT scan along with the traditional enteroclysis examination have emerged at the forefront of intestinal imaging. Functional modalities such as diffusion and perfusion imaging are also changing the way tumors and inflammatory bowel diseases are evaluated. CT colonography is now a valid alterative to optical colonoscopy. Contrast-enhanced USG is being used for the assessment of inflammation and post-treatment changes. In this review, recent advances in intestinal imaging are described.

Noninvasive imaging of the small bowel in Crohn's disease: the final frontier

The substantial morbidity and mortality associated with Crohn's disease underlines the importance of accurate assessment at presentation, during follow-up, when investigating complications, and when evaluating the response to therapeutic interventions. Accurate methods are required to quantify the severity and extent of disease.

Incomplete longitudinal fractures and fatigue injury of the proximopalmar medial aspect of the third metacarpal bone in 55 horses

REASONS FOR PERFORMING STUDY

Previous descriptions of incomplete longitudinal fractures and fatigue injury of the proximopalmar aspect of the third metacarpal bone (McIII) have focused on diagnostic imaging findings, especially in racehorses.

OBJECTIVES

To document the case details, clinical features, response to diagnostic analgesia, diagnostic imaging findings and follow-up data in a large group of horses with an incomplete longitudinal fracture or fatigue injury of the proximopalmar medial aspect of the McIII.

MATERIALS AND METHODS

Horses were included in the study if pain was localised to the proximopalmar aspect of the metacarpal region, with radiological evidence of an incomplete longitudinal fracture or generalised increased radiopacity in the proximopalmar medial aspect of the McIII, or focal increased radiopharmaceutical uptake (IRU) in the proximopalmar aspect of the McIII. Age, breed, gender, height, bodyweight, work discipline, work history, duration of lameness, clinical signs and responses to diagnostic analgesia were recorded. Radiographic and scintigraphic images were assessed subjectively and objectively.

RESULTS

There were 55 horses representing a broad spectrum of ages and work disciplines, 73% of which had radiological abnormalities. The majority had no localising clinical signs, although 73% of horses with radiological abnormalities showed a characteristic pattern of lameness. Lameness was generally worse in straight lines than in circles. Increased radiopharmaceutical uptake ranged from mild to intense in the lame limb; 14% of nonlame limbs had mild IRU. Of horses for which long-term follow-up was available, 98% returned to full athletic function.

CONCLUSIONS AND POTENTIAL RELEVANCE

Incomplete longitudinal fractures and fatigue injury of the proximopalmar medial aspect of the McIII may occur in horses of many types and sports disciplines, and are not confined to immature performance horses. They should be considered an important differential diagnosis for proximal metacarpal region pain.

Clinical applications of bedside ultrasonography in internal and emergency medicine

Ultrasonography (US) is an invaluable tool in the management of many types of patients in Internal Medicine and Emergency Departments, as it provides rapid, detailed information regarding abdominal organs and the cardiovascular system, and facilitates the assessment and safe drainage of pleural or intra-abdominal fluid and placement of central venous catheters. Bedside US is a common practice in Emergency Departments, Internal Medicine Departments and Intensive Care Units. US performed by clinicians is an excellent risk reducing tool, shortening the time to definitive therapy, and decreasing the rate of complications from blind invasive procedures. US can be performed at different levels of practice in Internal Medicine, according to the experience of ultrasound practitioners and equipment availability. In this review, the indications for bedside US that can be performed with basic or intermediate US training will be highlighted.

Ultrasonography findings and symptoms in acute rotavirus gastroenteritis

BACKGROUND

The aim of the present study was to better understand how clinical events in acute rotavirus gastroenteritis are depicted on ultrasonography.

METHODS

The relationship between abdominal ultrasonography and clinical course and symptoms was evaluated in 92 patients with acute rotavirus gastroenteritis (51 boys, 41 girls) with an average age of 30.7 ± 24.6 months.

RESULTS

Significant correlations were observed between ultrasonography score and duration of illness after ultrasonography (P = 0.0232). It was also interesting that ultrasonography findings (score: 3.1 ± 1.0 vs 3.6 ± 1.2; P = 0.0118), clinical symptoms (3.1 ± 1.7 score vs 3.8 ± 1.8 score, P = 0.0293), and duration of illness after ultrasonography (4.4 ± 1.4 days vs 3.8 ± 1.1 days, P = 0.0301) were significantly different between patients examined on ultrasonography < 1 day after illness onset (n = 50, but duration of illness after ultrasonography followed only in 42) and those examined ≥ 2 days after onset (n = 42, but duration of illness after ultrasonography followed only in 35).

CONCLUSION

The ability of abdominal ultrasonography to indicate severity of disease makes abdominal ultrasonography an important guide to therapy.

Abdominal ultrasound after colonoscopy with insufflation of carbon dioxide versus air

OBJECTIVE

To investigate whether the use of carbon dioxide (CO(2)) compared with air insufflation during colonoscopy improves ultrasonography after the procedure.

MATERIAL AND METHODS

In a double-blind trial, 30 patients were randomized to insufflation with CO(2) or air. Thirty minutes after colonoscopy abdominal ultrasound was performed. Immediately after ultrasonography, the ultrasound quality of the liver, gallbladder, biliary ducts, pancreas, spleen, kidneys, abdominal vessels, antrum, bowel, urinary bladder and prostate/uterus was evaluated for optimal ultrasound scanning quality, minor reduction of scanning conditions, major reduction of scanning conditions and unacceptable scanning conditions.

RESULTS

Ultrasound quality 30 min after colonoscopy was significantly better when using CO(2) insufflation instead of air (p<0.003). Significant improvement in imaging quality was observed for the liver, portal vein, splenic vein, all three divisions of the pancreas, aorta, coeliac trunk, superior mesenteric artery, iliac vessels, left kidney and uterus.

CONCLUSIONS

Ultrasound investigation can be done after a colonoscopy with CO(2) insufflation, whereas it is not recommended after a colonoscopy with air insufflation. In selected cases, this approach may enable and improve post-colonoscopy ultrasound scanning.

Epiploic appendagitis: an entity frequently unknown to clinicians--diagnostic imaging, pitfalls, and look-alikes

OBJECTIVE

Epiploic appendagitis is an ischemic infarction of an epiploic appendage caused by torsion or spontaneous thrombosis of the epiploic appendage central draining vein. When it occurs on the right side of the abdomen, it can mimic appendicitis and right-sided diverticulitis; whereas when it occurs on the left side of the abdomen, it is often mistaken for sigmoid diverticulitis. The purpose of this article is to review the diagnostic imaging of this entity.

CONCLUSION

Epiploic appendagitis is self-limited and spontaneously resolves without surgery within 5-7 days. Therefore, it is imperative for radiologists to be familiar with this entity.

Transabdominal sonography in assessment of the bowel in adults

OBJECTIVE

We describe the key sonographic features and technical aspects of assessment of bowel disorders in adults.

CONCLUSION

Initial imaging with transabdominal sonography in the radiologic evaluation of bowel disease in adults often is reserved for patients with equivocal historical, physical, and laboratory findings related to the gastrointestinal tract. Because of technologic advances and accumulated experience in interpretation of the images, sonography yields substantial information about gastrointestinal disorders.

Reproducibility of bowel ultrasonography in the evaluation of Crohn's disease

BACKGROUND

Bowel ultrasonography is increasingly used in the detection and follow-up of patients with Crohn's disease, but a limitation to its further diffusion is the lack of standardisation of ultrasonography parameters.

AIMS

This study aimed to standardise the most common bowel ultrasonography parameters in order to develop an unequivocal imaging interpretation and to assess bowel ultrasonography reproducibility.

PATIENTS

Twenty patients with Crohn's disease were examined.

METHODS

Six ultrasonographers (mean bowel ultrasonography experience=16 years) performed the study. They chose and discussed a common assessment methodology concerning eight ultrasonography parameters: bowel wall thickness, bowel wall pattern, bowel wall blood flow, enlarged mesenteric lymph nodes, mesenteric hypertrophy, abdominal free fluid, and stenosis or fistulae at four preliminary meetings. The day of the study operators were randomised to two rooms where they independently and in turn performed ultrasonography scans. Interobserver agreement was scored by kappa statistics.

RESULTS

Excellent k values were observed for bowel wall thickness (0.72-1). k Values were poor for bowel wall pattern (-0.22-0.85) and good for bowel wall blood flow (0.53-0.89). The presence of lymph nodes was reproducible (0.56-0.90) except in one case (0.25). Concordance on free fluid was excellent (0.85-1), whereas that on mesenteric hypertrophy was generally poor (0.14-0.69). Agreement was excellent for stenosis (0.81-1) whereas that for fistula was fair in room abscesses (0.31-0.48) and very good in room B (0.87-1).

CONCLUSION

Bowel ultrasonography signs used in Crohn's disease can be standardised as most of them showed a fair to good reproducibility. In particular, bowel wall thickness, the most relevant parameter for Crohn's disease detection, showed an excellent reproducibility.

Noninvasive ultrasound elasticity imaging (UEI) of Crohn's disease: animal model

Inflammation occurs in episodic flares in Crohn's disease, which are part of the waxing and waning course of the disease. Healing between flares allows the intestine to reconstitute its epithelium, but this healing results in the deposition of fibrotic scar tissue as part of the healing process. Repeated cycles of flares and healing often lead to clinically significant fibrosis and stenosis of the intestine. Patients are treated empirically with steroids, with their many side effects, in the hope that they will respond. Many patients would be better treated with surgery if we could identify which patients truly have intestinal fibrosis. Ultrasound elasticity imaging (UEI) offers the potential to radically improve the diagnosis and management of local tissue elastic property, particularly intestinal fibrosis. This method allows complete characterization of local intestine tissue with high spatial resolution. The feasibility of UEI on Crohn's disease is demonstrated by directly applying this technique to an animal model of inflammatory bowel disease (IBD). Five female Lewis rats (150-180g) were prepared with phosphate buffered solution (PBS) as a control group and six were prepared with repeated intrarectal administration of trinitrobenzenesulfonic acid (TNBS) as a disease group. Preliminary strain measurements differentiate the diseased colons from the normal colons (p < 0.0002) and compared well with direct mechanical measurements and histology (p < 0.0005). UEI provides a simple and accurate assessment of local severity of fibrosis. The preliminary results on an animal model also suggest the feasibility of translating this imaging technique directly to human subjects for both diagnosis and monitoring.

Sonographic examination of the appendix in acute infectious enteritis and acute appendicitis

PURPOSE

To use transabdominal sonography to determine the frequency of visualization of the adult normal appendix in patients with suspected acute infectious enteritis (AIE) compared with patients with acute appendicitis (AA) and a control group.

METHODS

A total of 296 patients divided into 3 different groups underwent sonographic examination, including 120 randomly selected asymptomatic patients, 91 consecutive patients with AIE, and 85 consecutive patients with AA. In the 3 groups, visualization rate, outer appendiceal diameter, presence or absence of inflamed periappendiceal fat, and location of the appendix were recorded.

RESULTS

The visualization rates of the appendix were 49.2%, 70.3%, and 96.5% for the control, AIE, and AA groups, respectively (P < 0.05). The mean +/- SD outer appendiceal diameters for the 3 groups were 4.5 +/- 1.2 mm, 4.5 +/- 1.4 mm, and 7.9 +/- 2.0 mm, respectively. The difference between outer appendiceal diameter in the control and AIE groups was not statistically significant. Periappendiceal inflamed fat was detected in all AA cases, but in none of the AIE cases.

CONCLUSION

The appendix was visualized more often in patients with AIE than in the control group, although the outer appendiceal diameter of the AIE group was not significantly different from that of the normal appendix seen in the control group.

Small-bowel obstruction: state-of-the-art imaging and its role in clinical management

Small-bowel obstruction (SBO) is a common clinical condition with signs and symptoms similar to other acute abdominal disorders. The radiologic investigation of patients with SBO as well as the indications and timing of surgical intervention have changed over the past 2 decades. This review focuses on modern imaging techniques and their role in both the diagnosis and treatment of patients with SBO.

Colonic diseases: the value of US examination

The colon is affected by a number of diseases, mainly inflammatory, ischemic, and neoplastic conditions. Depending upon clinical indications endoscopy, US, CT, or other radiological methods are used for evaluation. The fact that US is frequently used as the initial imaging method in patients with non-specific clinical symptoms allows for greater influence in further diagnostic evaluation and with treatment, provided the investigator is familiar with the features of different intestinal diseases. This article will describe the anatomical characteristics of the colon, the US technique for examination of the colon, and the typical US features of the more common diagnoses of the colon.

Prospective evaluation of contrast-enhanced ultrasonography with advanced dynamic flow for the diagnosis of intestinal ischaemia

This study aims to prospectively evaluate the importance of contrast-enhanced ultrasonography with advanced dynamic flow in the diagnosis of intestinal ischaemia in bowel obstruction. 50 patients admitted for bowel obstruction were included in this study. Of these, 17 patients had intestinal ischaemia (bowel strangulation, nine; superior mesenteric artery thromboembolism, four; non-occlusive mesenteric ischaemia, four), whereas 33 patients had simple obstructions. The definitive diagnosis of intestinal ischaemia was established by surgery. After administration of SHU 508A, the least peristaltic and/or the most dilated segments were imaged by this method. Colour signals depicted in the bowel wall were classified as normal, diminished or absent. The ultrasonographic findings were later correlated with the clinical outcomes and surgical findings. The colour signals were absent in 12 patients (bowel strangulation, six; superior mesenteric artery thromboembolism, four; non-occlusive mesenteric ischaemia, two), were diminished in four patients (bowel strangulation, two; non-occlusive mesenteric ischaemia, two) and were normal in 34 patients (simple obstruction, 33; bowel strangulation, one). Assuming that the diminished and absent colour signals indicate the presence of intestinal ischaemia, the sensitivity, specificity, positive predictive value and negative predictive value of the method were 94.1%, 100%, 100% and 97.1%, respectively. Our preliminary experience suggests that contrast-enhanced ultrasonography with advanced dynamic flow is a highly sensitive method for the diagnosis of intestinal ischaemia in patients with bowel obstruction.

The usefulness of transabdominal ultrasound for the diagnosis of lower gastrointestinal bleeding

BACKGROUND

Lower gastrointestinal bleeding is a frequent cause of hospitalization, but diagnostic methods for this condition are not fully established. Transabdominal ultrasound is a widely accepted diagnostic tool in bowel diseases.

AIM

To evaluate the usefulness of transabdominal ultrasound for lower gastrointestinal bleeding.

METHODS

We reviewed the medical records of consecutive patients who underwent transabdominal ultrasound as the first diagnostic procedure for acute haematochezia during the period June 1999 to June 2004. The study group comprised 111 patients and all underwent colonoscopy thereafter. Detection and diagnosis of lower gastrointestinal bleeding by ultrasonographic examination were evaluated by comparing the ultrasound diagnosis with the colonoscopic findings and final diagnosis.

RESULTS

The bleeding site was localized by colonoscopy in 90 of the 111 patients (81%). The bleeding site was localized by ultrasound in 59 of the 90 patients (66%). When the bleeding site was in the rectum, ultrasonographic detectability was 30% (10/33); ultrasonographic detectability was 82-100% when the bleeding site was elsewhere. Rectal bleeding and diverticular bleeding were difficult to diagnose by ultrasound, but for the other diseases, diagnosis by ultrasonographic examination was possible in 91-100% of cases.

CONCLUSIONS

Ultrasonographic examination may be an effective screening method for lower gastrointestinal bleeding.

Radiology of small bowel obstruction: contemporary approach and controversies

The radiologic workup of patients with known or suspected small bowel obstruction and the timing of surgical intervention in this complex situation have undergone considerable changes over the past two decades. The diagnosis and treatment of small bowel obstruction, a common clinical condition often associated with signs and symptoms similar to those seen in other acute abdominal disorders, continue to evolve. This article examines the changes related to the use of imaging in the diagnosis and management of patients with this potentially dangerous problem and revisits pertinent controversies.

Focal bowel wall changes detected with colour Doppler ultrasound: diagnostic value in acute non-diverticular diseases of the colon

We performed a study to determine if colour Doppler findings may help to identify the cause of wall thickening in acute non-diverticular diseases of the colon. The study group included 66 patients admitted to the emergency department with a final diagnosis of infectious colitis (n=23), inflammatory colitis (n=10), ischaemic colitis (n=23) and malignant tumours (n=10). The following ultrasound features were assessed: maximal wall thickness, wall stratification, arterial flow in the colonic wall and arteriolar resistive index. Higher values of wall thickness were observed in malignant tumour (18.2+/-6.2 mm, p<0.001). Moderately thickened wall (6.6+/-1.3 mm, p< or =0.06), preserved stratification (90% versus 46% in the remainder of the study population) and lower resistive index (0.51+/-0.10, p< or =0.05) were significantly related to inflammatory colitis. Absence of arterial flow was more frequently observed in ischaemia (43% versus 12% in the remainder of the study population). In conclusion, despite some overlap, both ultrasound and colour Doppler features are helpful in the differential diagnosis of colonic thickening related to non-diverticular colonic lesions.

The relevance of free fluid between intestinal loops detected by sonography in the clinical assessment of small bowel obstruction in adults

INTRODUCTION

The main role of the radiologist in the management of patients with suspicion of small bowel obstruction is to help triage patients into those that need immediate surgical intervention from those that require medical therapy or delayed surgery. Ultrasound examination is usually considered not helpful in bowel obstruction because of air in the intestinal lumen that interferes the evaluation of the intestinal loops, however recently some Authors attested the increasing important role of sonography in the acute abdominal disease. Aim of our report is to demonstrate the value of free fluid detected by US in differentiating between low and high-grade small bowel obstruction.

MATERIALS AND METHODS

The study is based on 742 consecutive patients who presented symptoms of the acute abdomen; all patients had undergone initial serial abdominal plain film and US examinations prior to any medical intervention. We reviewed the imaging findings of 150 cases in whom small bowel obstruction was clinically suspected and confirmed at surgery. We consider the following radiographic and US findings: dilatation of small bowel loops; bowel wall thickness; presence of air-fluid levels; thickness of valvulae conniventes; evidence of peristalsis; presence and echogenicity of extraluminal fluid. We looked at the value of extraluminal peritoneal fluid at US examination in differentiating low and high-grade small bowel obstruction based on the surgical outcome.

RESULTS

In 46 patients altered peristaltic activity, thin bowel walls, fluid filled loops with hyperechoic spots in the bowel segment proximal to obstruction were noted at US, whereas radiographic features were: moderate dilatation of small bowel loops, with thin bowel wall and evidence of numerous and subtle valvulae conniventes; presence of air-fluid levels was also noted. In 70 other patients, US examination revealed all the findings described in the precedent cases and also the presence of free extraluminal fluid; abdominal plain film showed an increased dilatation of small bowel loops with moderate thickened wall and air-fluid levels. In 34 other patients US examination revealed the presence of thick-walled loops, hypoperistalsis and a larger amount of free extraluminal fluid. Radiographic findings in these patients were: horizontal featured and markedly dilated small bowel loops presenting parietal thickness, presence of intraluminal fluid stasis and evidence of thickened, sparse and incomplete valvulae conniventes. At surgery etiology of small bowel obstructions was various, but most of cases related to adhesions (70 cases). The presence of extraluminal fluid were confirmed at surgery in 104 patients.

CONCLUSIONS

Our experience using sonography in suspicion of SBO (small bowel obstruction) suggests the usefulness of this imaging modality to differentiate a functional or obstructive ileus, demonstrating the evidence of intestinal peristalsis. Furthermore, the presence of a large amount of fluid between dilated small bowel loops suggests worsening mechanical small bowel obstruction, that requires not a medical therapy but immediate surgery.

Sonographic diagnosis of colitis in children

To assist the radiologist in differentiating the colitis in children, this review proposes a systematic US approach to the disease, presents the US aspect of the normal colon and describes three distinctive US patterns reflecting the intramural extension of the histopathological changes. Each pattern corresponds to one or several diseases producing alterations in the same layer(s). Stratified thickening suggests an inflammatory mucosal process resulting from infection (as in advanced appendicitis or in infectious colitis) or to inflammation (as in IBD). Nonstratified thickening with loss of the haustral folds reflects a marked submucosal infiltrate. Color Doppler is required to distinguish between an inflammatory disease (as advanced CD or neutropenic colitis) and an ischemic colitis (HUS in children). Nonstratified thickening with preservation of the length of the haustral folds is the sign of an intraluminal deposit due to PMC. Correlating the sonographic pattern and the anatomic distribution of the disease with the clinical and laboratory findings often permits to propose a specific diagnosis.

Ultrasonography of the acute abdomen

Although multislice, helical CT is increasingly replacing ultrasonography for the evaluation of patients with acute abdominal pain, ultrasound does have certain specific advantages over CT. This article discusses the advantages of ultrasound in imaging of the acute abdomen, exploring such areas as appendicitis, ileocecal Crohn's disease, infectious ileocolitis and infectious ileocecitis, mesenteric lymphadenitis, cecal carcinoma, sigmoid diverticulitis, right-sided colonic diverticulitis, and perforated peptic ulcer.

Abdominal pain among children re-evaluation of a diagnostic algorithm

AIM: To re-evaluate the algorithm that has been used for over 40 years for diagnosis of acute abdominal pain among children.

METHODS: Among the 937 cases admitted to the surgical emergency ward in 2000, 656 cases of acute appendicitis were studied to evaluate the usefulness of the present algorithm for its calculated accuracy, false positive and false negative rates, the sensitivity and specificity in the instant diagnosis of various types of acute appendicitis in different age groups. The algorithm used was established in 1958 and revised for this study in 1999. It includes a 3-step analysis of clinical presentations, i.e.: firstly, a diagnosis of surgical pain by definite organic abdominal signs; then a diagnosis of the subgroup of surgical condition by special signs; and finally the diagnosis of the present disease by specific signs. A footnote describes a "comparative technique" of abdominal examination in non-cooperative children.

RESULTS: The general accuracy of diagnosis was 92.8%, overall mortality 0.1% among 973 cases of abdominal pain in 2000.373 attending surgeons and 241 residents including trainees joined the diagnosis and treatment with no remarkable difference in the results. The incidence of acute appendicitis, 656 in 973 cases, was 67.4% representing the majority of abdominal pain. In the series of 656 cases, the accuracy of diagnosis of acute appendicitis was 93.6%, false positive 6.4%, false negative 0.9%, sensitivity at first visit 82.7%, specificity for appendicitis 98.0%, no death or documentary complication.

CONCLUSION: The present algorithm used for diagnosis of acute abdominal pain is effective and preferable in reducing misdiagnosis and maltreatment at emergency. The use of some modern technology should be further explored.